Calculating machine



H. T. AVERY CALCULATING MACHINE Sept. 16, 1941.

2 Sheets-Sheet 1 Filed Oct. 7, 1936 'OQQQQQOOQ OOOOOOOO/OO INVENTORHare/d T/Iw/y ATTO EY.

Sept. 16,1941. AVERY 2,255,909

CALCULATING MAcHiNE Filed Oct. '7, 1936 2 Sheets-Shut 2 INVENTOR. I

AT TORN y Patented Sept. 16, 1941 OFFICE CALOUIATING MACHINE Harold '1.Avery, Oakland, Calif., minor to Marchant Calculating Machine ration ofCalifornia c pa y, r

Application October I, 1936, Serial No. 104,471

lclalm.

The present invention relates to keyboard controlled machines, and isdisclosed as applied to calculating machines.

This application is a continuation-impart of application Serial No.653,207, filed January 23, 1933, and since matured into Patent Number2,229,630, issued on January 28, 1941, and of application Serial No.702,949, filed December 18, 1933, and since matured into Patent Number2,211,736, issued on August 13, 1940, disclosing calculating machines ofa. type to which the present invention is adaptable,

It is an object of the present invention to provide an improved keyboardconstruction.

It is an object of the invention to provide a keyboard composed ofremovable sections separately adjustable as to their cooperativerelation with the machine.

Other objects and advantages will appear in the following specification,wherein the preferred form of the invention has been disclosed, when thesame is read in connection with the accompanying drawings in which:

Figure 1 is a plan view of a keyboard embodying the invention, certainparts being broken y;

Figure 2 is a side elevational view, partly in section, of a single bankof keys with portions oi the supporting and cooperating devices;

Figure 3 is an enlarged sectional view taken on the line 2-3 of Figure2; and

Figure 4 is a detail view of the resilient limit stop device.

In a machine designed for calculation in th decimal system, the keys arepreferably arranged, as shown in Figure 1, in a series of banks oi tenkeys each with decimal bars lying between each pair of key blanks, thenumber of banks provided in each machine depending upon the magnitude ofthe factors with which the machine is designed to deal.

Details of the construction of one bank of keys are shown in Figures 2and 3 of the drawings. Each key section comprises the usual number ofvalue keys 30, which are slidably mounted in a channel key frame IN, andare normally maintained in raised position by suitable coil springs I02.The key stems I03 are assembled into the channel irame IOI (see Figure3) by insertion irom the top, the slot I 04 in the upper side of thechannel member being 01 suflicientwidth to pass the projection I 05 orthe key stem, but the aligned slot Hit in the lower side being of lesserwidth, so that the key stem cannot drop through;

the projection I05 being adapted to outset the iowcr portion of thechannel i0l adjacent slot I00 to provide a limiting stop.

After the key stems l03,have been inserted, they are retained bysecuring to the irame member IN a channelled retainer I01 adapted to beheld in place by means such as screws I08. Within the retainer- 101 is astrip of buffer material 109, preferably spring metal, portions H0 ofwhich lie adjacent apertures III in the sides of the retainer nearestprojections I05 oi the keys. This strip I09 is also formed with ofisetportions II2 so proportioned as to be slightly deflected as the strip isinserted within retainer Ill, thus maintaining the strip under lightconstant tension. The upturned ends II3 oi. the strip are adapted toproject beyond the ends oi retainer I01 and assist in preventingaccidental displacement oi the strip.

As a key stem I03 is moved upwardly by spring "2, projection I iscarried against a portion H0 oi the strip I08 which may yield to providea cushioned stop for the key. The noise incident to release of the keysfrom their latching means is thus substantially reduced.

Each key section is mounted in the machine between members H5 and Hiwhich extend between the side plates oi. the machine. Each end of thechannelled key frame IN is slotted as at II! (Figure 1) so that thelongitudinal position of the key section may be adjusted, each keysection being secured in the desired position by the screws 0. After theseveral key sections have been positioned, flat decimal markers I20 arenositioned and suitably journaled between each bank of oval keys. Aknurled finger piece I2I extends through a cover member I22 so that theflat decimal marker can be rotated to expose either of its sides, themarkers being shown in position occupied while the markers are beingturned in Figure 2. As is well known, one side of these markers iscolored to correspond with the coloring of the top of channels Ilil,while the other side thereof is colored contrastingly, so that byturning selected'markers the keyboard may be set oi! decimaliy in anydesired manner. Due to the shape of the keys, view of the markers isunobstructed despite compact assembly of keys and markers.

50 All the key stems are of the same length and each has a cam extrusionI25 which, upon depression of the key, pushes a slotted key lockingslide I20, slidably supported on the lower side of channel III, to theright, as viewed in Figure 2, releasing any other latched-down key inthe the two different positions in Figure 1, and in a.

same section. Upon full downward depression of the respective key stem,this slide IZS, pressed forward by spring I21, snaps back to initiallocation and, by overlying the upper end of extrusion I25, locks thedepressed key.

The leftmost key (Figure 2') in each section is the zero or clear key,and is provided for the sole purpose of releasing any latched-down keyin the same section. The stem W3 and the extrusion I25 of this key areidentical with the other keys of the section, but latching down of thekey is prevented by the provision, on the locking slide I26, of a lipI28, the lower edge of which lies below the lowest position assumed bythe top of extrusion I25. Hence, while the slide is moved to the rightupon depression of this key, the lip I28 prevents it from returningleftward during the depression of the key, and latching of the key cannot be effected.

When a numeral key stands depressed and it is desired to depress adiiierent numeral key in the same section, .the first key must bereleased during the first part of the stroke of the second key in orderto avoid interference between the respective key stems in moving theV-slot bar 830. For this reason the lower edges of extrusions I25normally lie closely adjacent they looking slide I26. However, in orderto avoid inadvertent release of keys when the person or clothing of theoperator touches the zero keys, the lip I28 of each locking slide, bymeans of which it is moved by the associated zero key, is formed awayfrom the cooperating extrusion I25 for a substantial part of its length,as shown in Figure 2, so that the extrusion does not move the slideuntil the key has moved downwardly through about half of its stroke.Since the zero keys do not contact the V-slot bar I30, this causes noin-- terference.

Disposed underneath the value keys "one to nine, inclusive, is adifferentially settable bar I30 which is pivotally suspended from thekey' section frame Iill by means of two parallel links I3I and I32. Thisbar I33 has nine identical notches I33, each of which has at its bottoma downwardly extending slot I36 adapted to receive the lower end of akey stem I03. The vertical center lines of the key stems I03 are spacedequal distances apart. This distance, however, is slightly greater thanthe spacing between successive slots I34, so that each succeeding slotwe will be spaced one increment farther away from its cooperating keystem I03. This spacing is thus proportioned in such a way thatdepression of a value key will cam the bar I30 to the right, as viewedin Figure 2, a number of increments equal to the value represented bythe depressed key.

The longitudinal position of each key section is adjusted by a screw I35(Figure 2) which engages an ear I36 on the channel frame II and isthereafter locked by nut l3! against bar H5.

The section can thus be removed and replaced repeatedly withoutdisturbing the adjustment.

Movement of each bar I30 is utilized to set up a mechanicalrepresentation of the selected value whereby the calculating mechanismmay be accordingly controlled. A swinging segment member M0 is mountedupon a common shaft Hi which supports like members associated with otherkey banks. This member is provided at opposite ends with arcuate racksM2 and 3, which serve to transmit the movement of the differential barI39 respectively to a check dial assembly I44 positioned on shaft M5 inalignment with similar dials associated with the other key sections sothat the value set up on the entire keyboard is read in a straight lineof dials, and to mechanism which is positioned by such movement so as toform a mechanical representation of the number set up whereby thecalculating mechanism may be accordingly controlled.

I claim:

In a' calculating machine, a key section comprising a channel memberhaving aligned upper and lower slots formed in the flanges thereof withthe upper slot of greater length than the lower, a plurality of flat keystems movable in said slots and each formed intermediate its ends withan extensiom and means for retaining said stems in the member comprisinga single removable retainer secured within said member in position forengagement by said extension.

' HAROLD T. AVERY.

